The Food and Drug Administration (FDA) is the federal body that “is responsible for protecting the public health by assuring the safety, efficacy, and security of human and veterinary drugs, biological products, medical devices, our nation's food supply, cosmetics, and products that emit radiation.” (FDA Mission Statement).
In order for the FDA to execute its mission of ensuring the public health and safety as related to food and drugs, numerous persons involved with the production of pharmaceuticals, chemicals, and the like, are required by statute or regulation to maintain records or submit information to the FDA.
As computers have become ubiquitous and their storage capacity has increased many times over, it has become increasingly common for such persons to want or even have to create, store and submit electronic records or information in lieu of paper records or information.
In March of 1997, in response to this continuing change in the manner of keeping and submitting records, the FDA issued final regulations that provide criteria for FDA acceptance, under certain circumstances, of electronic records as equivalent to paper records. The FDA issues all of its governing regulations within Title 21 of the Code of Federal Regulations (CFR). The new electronics records regulations were issued as 21 CFR Part 11, or simply “Part 11.” The 21 CFR Part 11 regulations became effective in August 1997.
21 CFR Part 11 imposes specified controls and requirements onto the creation, storage, and use of electronic records. The intent was to make electronic records useable in lieu of paper records. Nonetheless, there has been a great deal of uncertainty as to how to how best comply with Part 11. This is especially true in the process control and data analysis context since the configuration and use of equipment and the associated collection, recordation, analysis, and process control use of data has been accomplished with a disjointed collection of electronic records and paper records that are created and used in a myriad of different ways during the operation of the process and, moreover, a disjointed collection of users that create and use such records, by and large, independently of any computer system that may be involved in storing of such records.
There remains a need, therefore, for a system that automatically and comprehensively manages the creation, storage and use of electronic records during the operation of a controlled process and for governing and documenting the users that operate the computer systems that are involved in the creation, storage and use of the electronic records and the changes that such users make to the process.
As further background, systems for controlling processes are well known. A large variety of different processes are used in the manufacturing and testing of products such as pharmaceuticals, petroleum derivatives, chemicals, materials, integrated circuits, semiconductors, foods, cosmetics, automobiles, consumer electronics and many other items. Both manual and automatic control systems for such processes are commonly used.
Manual control systems are operated by a person. The person monitors the process and makes adjustment thereto as needed. Because manual control systems are operated by a person, they are subject to error and inconsistency. Manual control systems are subject to error because people are subject to making errors. People are also subject to fatigue, which increases the likelihood of error. Manual control systems are subject to inconsistency because people inherently rely upon subjective decision making processes.
Automatic control systems are operated by a machine, such as a microcontroller or general purpose computer. The machine monitors the process and makes adjustment thereto as needed. Because automatic control systems are operated by a machine, they are generally less subject to error and inconsistency than are manual control systems. Generally, a machine can be made to perform a task in a precise and reliable manner, such that errors are minimized. Machines are not subject to fatigue in the same sense that people are, so machines are not generally more likely to make errors after a long shift. Automatic control systems are less subject to inconsistency than people because machines can be made to rely upon objective decision making processes.
A control system, whether manual or automatic, generally receives at least one input which is representative of some parameter associated with the process. Based upon the value of the parameter, decisions are made regarding if and how the process is to be modified. These decisions are generally made according to predetermined rules.
The number of inputs to a control system can be large and the amount of data associated with such inputs can be large. The rules for determining desired responses to the inputs can be complex, especially when there are many ways in which the process can be modified. The time allowed for making a decision can be very small. Typically, the cost of providing a machine to operate an automatic control system is less than the cost of providing a person to manually control the same process. In many instances, these factors necessitate that a machine be used for process control.
Because of these and other advantages of automatic control systems, the use of machines to control processes is widespread. However, although contemporary automatic control systems have proven generally suitable for their intended purposes, they possess inherent deficiencies which detract from their overall effectiveness and desirability. For example, many times it is desirable to control one or more processes from a computer that is located remotely with respect to where the process is being performed. However, according to contemporary practice, the distance between a computer that is controlling a process and the process itself is limited.
In an attempt to facilitate such remote control of a process, a computer can be wired so as to provide communication with one or more measurement devices (devices which monitor the process) and one or more control devices (devices which are being controlled as part of the process).
For example, a process control computer located in a chemist's office can be wired so as to receive input signals from several spectrometers which are located on the production floor of a pharmaceutical manufacturing facility. The same process control computer can be wired so as to provide output signals to flow control valves located on the same production floor or elsewhere. The process control computer may be hundreds of feet from the spectrometers and/or the flow control valves. Indeed, the process control computer does not even have to be located in the same building as the spectrometers and/or flow control valves.
While such interconnection of the computer, the spectrometers, and the flow control valves does provide enhanced functionality with respect to control systems that required a dedicated microcontroller or other type of collocated control device, such interconnection suffers from inherent disadvantages.
For example, the lengths of the wires from the spectrometers to the computer and the lengths of the wires from the computer to the flow control valves are limited. Unless some type of repeater, amplifier, or signal conditioning device is utilized, the distance between the computer and either the spectrometers or the flow control valve generally cannot be greater than several hundred feet. The use of such repeater, amplifier, or signal conditioning devices is generally undesirable because of the expense associated therewith, the reliability thereof, and/or the inherent signal delays caused thereby.
As such, although the prior art has recognized, to a limited extent, the problem of controlling processes from diverse locations with respect to measurement devices (such as spectrometers) and control devices (such as flow control valves), the proposed solutions have, to date, been ineffective in providing a satisfactory remedy. Therefore, it is desirable to provide a process control system wherein the measurement devices and the control devices may generally be disposed at any desired location and the computer or other controller thereof may generally be located at any other desired location.